Air bag restraint systems are used in vehicles such as automobiles to help reduce the extent of personal injuries incurred in vehicular accidents. Air bags are designed to inflate during a collision to restrain movement of the driver and/or other occupants to help avoid injurious contact with interior portions of the automobile. They are typically stowed behind a cover door in one or more interior trim structures, such as the steering wheel cover, door panel, or dashboard. The cover door is attached to, or formed as part of, the interior trim structure in such a manner as to inhibit access through the door opening from outside the door (e.g., by an occupant of the vehicle), and to open under the force of an expanding air bag to permit the air bag to expand out through the opening and into the interior of the vehicle.
Common deployment locations within an automobile for air bag restraint systems include, for the driver, the center hub of the steering wheel and, for a front seat passenger, either the top (horizontal) or rear-facing (vertical) surface of the dashboard. Other deployment locations include door panels, seats, and headliners. Cover doors for air bag deployment openings that are located in a generally horizontal opening in the dashboard are referred to as top mount cover doors and cover doors for deployment openings located in a generally vertical opening in the dashboard are referred to as mid-mount doors. Examples of top mount air bag cover doors are disclosed in U.S. Pat. Nos. 4,893,833 to A. J. DiSalvo et al., 4,964,653 to K. L. Parker, and 5,154,444 to E. S. Nelson. Examples of mid-mount doors are disclosed in U.S. Pat. Nos. 3,708,179 to R. E. Hulten and 4,895,389 to W. D. Pack, Jr. PG,4
As shown in the patents to DiSalvo et al. and Parker, top mount cover doors are commonly designed to pivot along a front edge of the door so that the door swings upwardly and toward the automobile's windshield. As the air bag inflates it moves upwards through the door opening and rearwardly towards the front passenger seat. A duality of problems can arise from this arrangement. First, the forceful opening of the air bag cover door by the inflating air bag causes the door to swing open with sufficient force and speed that the cover door can contact and even break the automobile's windshield. Second, since the deployment opening is located in a generally horizontal orientation, the air bag must first move upwards as it exits through the door opening, even though the desired direction of inflation is rearward toward the front passenger seat.
Cover doors for front passenger restraint systems are typically secured along an edge of the cover door, either by a releasable fastener or otherwise. It is known to use hook and loop tape as a releasable fastener to maintain the cover door closed until deployment of the underlying air bag. See, e.g., U.S. Pat. No. 5,161,819 issued Nov. 10, 1992 to R. D. Rhodes, Jr. Although suitable for maintaining a tamper-resistant closure of the cover door, the arrangement disclosed in that patent only restricts the opening of the door initially--it does not limit the speed of the cover door as it swings open. Rather, once the hook and loop tape separates, the door is free to swing open with as much force as is imparted to it by the expanding air bag.